Abstract

Fire Steel 5L X-52 is pipe which is made and produced based on standart API that is American Petroleum Institute which this pipe has carbon grade 0,3 % ( journal data Iscor Flat Steel) that is included in medium carbon steel. Problems that is often happened at result of welder SAW ( Submerged Arc Welding) at fire steel 5L-X52 among others is incidence of residual stress and the forming of microstructure in the form ( martensite, retained austenite and carbide) what can reduce ductility or toughness so that doesn't fulfill standart API (American Petroleum Institute). To overcome this problem heat treatment influence stress relief would good for increasing toughness of weld and endurance to speed of propagation of phatic crack at pipe connection of fire steel spiral 5L X-52.
Purpose of performed a by this research is aim to improve;repair endurance of speed of propagation of phatic crack at result of welder ( SAW) with treatment of stress relief annealing.
From result of research is obtained by conclusion for heat treatment with temperature 5500C, 6500C, 7500C at district Las that for weld metal from steel API 5L X-52 is gotten by propagation of best phatic crack at temperature 5500C with propagator value (ai) 2/10 mm and at cycle (ni) 65155 at temperature 6500C with propagator value (ai) 1,5/10 mm and at cycle (ni) 61547 at temperature 7500C with propagator value (ai) 6,5/10 mm and at cycle (ni) 46633